The New York Mets placed their oft-injured left fielder on baseball's seven-day DL for concussions Saturday and activated infielder Justin Turner from the 15-day disabled list.
After missing six weeks this season with a broken rib, Bay was hurt again Friday night when he crashed into the outfield wall while trying to catch Jay Bruce's inside-the-park home run for Cincinnati.
Mets manager Terry Collins said Bay has been told to stay home and rest for a couple of days until he's examined by doctors. Collins isn't sure how long Bay will be sidelined but expects it to be more than seven days.
Bay missed the final two months of the 2010 season with a concussion he sustained slamming into the left-field fence to make a catch at Dodger Stadium.
"I'm very worried about it because Jason's first one was pretty severe and he hit the wall pretty hard yesterday," Collins said. "He's pretty sore today. Real sore. So we're just going to have to, again, bide our time and see how he comes out of it in the next few days and see how he feels."
It's the latest setback for Bay, a pricey bust in New York due to injuries and a lack of production at the plate.
The three-time All-Star signed a $66 million, four-year contract with the Mets in January 2010 after setting career highs with 36 homers and 119 RBIs for Boston in 2009. But he played only 95 games in his first season with New York and 123 last year. He has missed 44 out of 66 games this year, leaving him with just 22 homers and 110 RBIs in two-plus seasons with the Mets.
The 33-year-old Bay is batting .187 with four home runs and six RBIs. He was on the disabled list from April 24 until June 6 with a broken rib and went 2 for 25 with a home run after being activated.
A week after returning to the lineup, he got hurt again.
Bay is not the only Mets player with a history of head injuries. New York catcher Josh Thole has also had multiple concussions, one of which landed him on the disabled list from May 8-31.
"I know what he's feeling. I know what he's going through. It's not easy," Thole said. "It gets scarier because you go sit in the doctor's office and the doctor tells you you could be one away if you have a serious one. It's stuff you don't want to hear."
Scott Hairston was set to start in left field Saturday night against the Reds. Collins said he'll "mix and match" in the outfield while Bay is out, and the backups on the bench are versatile enough that the Mets can stick with what they have on the roster right now.
Turner had been on the DL since May 29 with a sprained right ankle. He played two rehab games at Triple-A Buffalo.
Collins said the Mets would be careful with Turner because his ankle still gets sore in the morning and takes a little while to loosen up. The reserve infielder was not in the starting lineup Saturday.
With starting shortstop Ruben Tejada sidelined since May 7 with a strained right quadriceps, Collins said he hopes to have backup Ronny Cedeno (strained left calf) back by the middle of next week.
Tejada was slated to run again Saturday and Collins said he hopes Tejada can play in a rehab game by Monday.